The traditional law of insufficiency is derived from the conception of the disclosure in a patent specification as the patentee's consideration to provide to society at large as the quid pro quo for a patent monopoly in a contractual sense, and can be traced back to Liradet. The general concept of disclosure in modern insufficiency established thereby was further developed and molded in UK statutory law that most relevantly raises insufficiency as revocation ground. The requirement set out thereby is that a patent specification shall constitute an enabling disclosure of the invention claimed in the claims, and thus, a specification is deemed insufficient if a person skilled in the art that follows the express teaching of the disclosure cannot perform the invention at all or without a prolonged, research, enquiry or experiment.
In addition, the common law doctrine of undue claim width comprises this insufficiency principle, in particular with regard to claim objections to an unduly breadth relative to the extent of disclosure, i.e. for covetous claiming.
The so-called Biogen insufficiency goes further and hearkens back to the development of chemical product claims in the UK’s early 20th century when chemical inventions were limited to product-by-process claims. At those times, any chemical product had to be defined by its distinct method of processing. This said, the development and shortcomings of this particular patent claim category were well known, but although the House of Lords (HoL) was dealing with product-by-process claims in Biogen, it held that this claim category comes under the same judicial consideration as applied to simple product claims with regard to sufficient disclosure, and therefore, it is insufficient if a person skilled in the art is enabled by the disclosure to perform a single embodiment of the claimed invention by following the teaching of the specification.